Any Tory MP can throw his or her hat into the leadership ring, requiring just a proposer and seconder.

BBC: A cumbersome procedure

They must also find the backing of at least two members of the Liberal Democrat parliamentary party - one proposer, and one seconder.

BBC: The path to leadership

Treasury spokesman Malcolm Bruce has the backing of three, while Simon Hughes, Don Foster, David Rendel and Jackie Ballard have just two MPs each to act as proposer and seconder.

BBC: News | UK Politics | Lib Dem contenders compete for MPs' support

Then Ed Miliband, as Leader of the Opposition, has a go - the normal courtesies require him to compliment the mover and seconder, and remember MPs who've departed this life, before moving on to the bills the government has announced.

BBC: Week ahead